<%@ page language="java" 
    pageEncoding="utf-8"%>
<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>
<%@ taglib uri="http://java.sun.com/jsp/jstl/functions" prefix="fn" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>Insert title here</title>
</head>
<body>
<c:set var="string1" value="This is first String."/>
<c:set var="string2" value="This is second String." />

<p>字符串长度 (1) : ${fn:length(string1)}</p>
<p>字符串长度 (2) : ${fn:length(string2)}</p>
</body>
</html>